WO2021134454A1

WO2021134454A1 - Composition for cosmetic products

Info

Publication number: WO2021134454A1
Application number: PCT/CN2019/130450
Authority: WO
Inventors: Ya HU; Qingsheng Tao
Original assignee: L'oreal
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2021-07-08
Also published as: CN115209859A

Abstract

It relates to an oil-in-water (O/W) microemulsion composition useful in a product for caring for keratin materials, comprising: an oil phase comprising (A) a fatty acid-ester mixture; and an aqueous phase comprising (B) a solvent, e.g., water and/or at least one alcohol, and (C) at least one non-ionic surfactant.

Description

Composition for cosmetic products

Technical field

The present invention relates to a composition useful in cosmetic products, especially in products for caring for and/or cleansing keratin materials, in particular the scalp.

Background

Keratin materials are present widely on surface of human bodies, e.g., skin, scalp and hair. Many people have for a long time sought to soothing the body surface, so as to feel comfortable in daily life and work. Amongst others, the feeling of itch is particularly concerned by many people. Various factors may cause the feeling of itch, e.g., high dryness of body surface, presence of certain bacteria on body surface, allergy, external stimuli or even psychological feeling, etc. Accordingly, various products are developed to deal with the itchy feeling of person, many of which are used to soothe the feeling of itch. In particular, considering the various factors, soothing the feeling of itchy is usually more feasible and meaningful than therapeutic treatment against directly the factors.

In the keratin materials on body surface, the scalp is particularly readily to suffer from itch. Various formulations have been developed for the itchy scalp, including those provided in a separate form, e.g., lotion, spray and the like, and those incorporated into conventional products for hair and/or for scalp, e.g., shampoo, leave-on and/or rinse-off conditioner.

In additional to the functions of cleansing and conditioning, some other properties are also important to attract consumers, e.g., special fragrance and good appearance. For example, some consumers like a transparent appearance.

Meanwhile, various emulsions, e.g., an emulsion obtained by dispersing a fatty phase in an aqueous phase (O/W) , an emulsion obtained by dispersing an aqueous phase in a fatty phase in (W/O) , or a multiple emulsion (W/O/W, O/W/O) , are widely used for cosmetic products. The stability of emulsions is thus quite interested, especially for a product having desirably a transparent appearance. It is known that the stability of emulsions ordinarily increases with decreasing the particle size of emulsions. Accordingly, it is known that microemulsion is widely used, as it is thermodynamically stable.

On the other hand, for cosmetic uses, natural ingredients, i.e., ingredients of natural origin, are of great interest to the consumers. Many compounds with natural origin are used in formulating compositions for caring for and/or making up of keratin materials. Efforts have been made to formulate compositions comprising natural ingredients.

There is thus still needed in the art to develop various intermediates, e.g., compositions, formulations, complex, composite and the like, for preparing products satisfying the consumers’ demand for multiple functions as well as apparent attraction.

Summary of the invention

In medical science, medium chain fatty acids and the respectively corresponding monoglycerides have been disclosed to have a broad spectrum of anti-microbial activity against enveloped viruses and various bacteria in vitro (Kabara, 1978; Shibasaki and Kato, 1978; Welsh et al. 1979 Thormar et al., 1987; Isaacs et al. 1995) , comprising but not limited to human pathogens such as herpes simplex virus, Candida albicans, Chlamydia trachomatis, Nesseria gonorrhoeae, Helicobacter pylori and Staphylococcus aureus. The inventors have now discovered that the use of a fatty acid-ester mixture of a plurality, e.g., at least 3, 4, or 5, of medium chain fatty acids and monoesters of the respective medium chain fatty acids with a lower polyol, makes it possible to obtain a composition for caring for keratin materials, which can non-therapeutically soothe the itchy feeling occurring on the keratin materials, especially on scalp.

One subject of the present invention is thus an oil-in-water (O/W) microemulsion composition useful in a product for caring for keratin materials, comprising:

an oil phase comprising a fatty acid-ester mixture of a plurality, e.g., at least 3, 4, or 5, of medium chain fatty acids and a plurality, e.g., at least 3, 4, or 5, of monoesters; and

an aqueous phase comprising water, at least one alcohol and at least one non-ionic surfactant.

The composition according to the present invention is particularly useful for a product for caring for keratin materials, such as shampoo, hair conditioner, scalp care conditioner, skincare products, and so on.

According to an embodiment of the invention, the fatty acid-ester mixture is a derivative of coconut oil, called as activated virgin coco oil (AVCO) .

The inventors have further surprisingly discovered that the use of a specific solubilizer, preferably a non-ionic surfactant, can benefit the composition of the invention to obtain a stable microemulsion, which can in turn benefit the cosmetic product to have a transparent appearance.

Notably, as introduced above, although medium chain fatty acids and monoglycerides thereof are known to have anti-microbial activity, various factors may cause the feeling of itch. The composition of the invention has been discovered, and also has been proved through experiments, that itchy feeling can be successfully soothed. Without being restricted to any known theory, it is believed that the successful use of the composition of the invention to soothe the itchy feeling contributes at least a part to the sensory relax to the keratin materials by the composition of the invention. Accordingly, the composition of the invention is limited to non-therapeutic uses, though it may be discovered further properties and/or mechanisms for a therapeutic use in the future.

Embodiments of the invention

Throughout the description, including the claims, the term "comprising a" should be understood as being synonymous with "comprising at least one" , unless otherwise mentioned. Moreover, the expression "at least one" used in the present description is equivalent to the expression "one or more" .

Throughout the description, including the claims, an embodiment defined with “comprising” or the like should be understood to encompass a preferable embodiment defined with “consisting substantially of” and a preferable embodiment defined with “consisting of” .

Other than in the operating examples, or where otherwise indicated, all numbers expressing quantities of components and/or reaction conditions are to be understood as being modified in all instances by the term "about, " meaning within 10%of the indicated number (e.g. "about 10%" means 9%-11%and "about 2%" means 1.8%-2.2%) .

Throughout the description, including the claims, the “keratin material” according to the present invention is the skin, hair, scalp, eyelashes, eyebrows, bodily hair, nails, lips or mucous membranes. Preferably, the keratin material according to the present invention is a position where an itchy feeling is easily felt, e.g., scalp, or skin, and/or a position where the itchy feeling has an impact on, e.g., hair.

Throughout the description, including the claims, the “care for” , “caring for” and the like according to the present invention should be understood to encompass any means to take care, maintain or improve the status of keratin materials, including not only the conventional means of caring for keratin materials, e.g., skin or scalp, but also any means known to be useful for conditioning and/or cleansing keratin materials, e.g., hair or scalp.

In the application, unless specifically mentioned otherwise, contents, parts and percentages are expressed on a weight basis.

The present invention is directed to an oil-in-water (O/W) microemulsion composition useful in a product for caring for keratin materials, comprising:

an oil phase comprising

(A) a fatty acid-ester mixture comprising:

(A-I) . a fatty acid component comprising a plurality, e.g., at least 3, 4, or 5, of medium chain fatty acids, and

(A-II) . an ester component comprising a plurality, e.g., at least 3, 4, or 5, of monoesters of medium chain fatty acids;

wherein the medium chain fatty acid denotes a monocarboxylic acid having 6 to 20 carbon atoms; and

an aqueous phase comprising

(B) a solvent, e.g., water and/or at least one alcohol, and

(C) at least one non-ionic surfactant.

Throughout the description, including the claims, the “microemulsion” according to the present invention means a thermodynamically stable isotropic liquid phase system containing at least three ingredients of an oily component, an aqueous component and a surfactant, in which the dispersed phase has a relatively small droplet size. Specifically for an O/W microemulsion, the dispersed oils have droplet sizes essentially below 300 nm, i.e. more than 50%and preferably more than 80%of the droplets are below 300 nm in size, preferably below 200 nm. Generally, a microemulsion can be subjected to a centrifugation at a centrifugal force of up to 100 G for at least 5 minutes without significant phase separation. Furthermore, a microemulsion is transparent, which is with a turbidity of less than or equal to 400 NTU, preferably less than or equal to 100 NTU, more preferably less than or equal to 10 NTU, more preferably less than or equal to 5 NTU, more preferably lower than 3 NTU, andeven more preferably lower than 2.5 NTU; evaluated by a HACH 2100AN turbidmeter (Loveland, USA) . The lower the turbidity, the better transparency of the microemulsion.

Preferably, the monoesters of the ester component (A-II) are respectively obtained from esterification of the medium chain fatty acids used in component (A-I) with a lower polyol.

Preferably, the fatty acid-ester mixture is a derivative of coconut oil, called as activated virgin coco oil (AVCO) .

The present invention thus provides use of the fatty acid-ester mixture for soothing the feeling of itching of keratin materials on body surface, especially scalp.

Other characteristics and advantages of the invention will emerge more clearly on reading the description and the examples that follow.

Oil phase

The oil phase comprises at least one oil. The term “oil” refers to any fatty substance in liquid form at room temperature (20-25℃) and atmospheric pressure. These oils may be of animal, plant, mineral or synthetic origin.

The oil phase of the microemulsion composition according to the present invention comprises a fatty acid-ester mixture (A) .

Fatty acid-ester mixture (A)

The composition of the present invention comprises a fatty acid-ester mixture (A) of a plurality, e.g., at least 3, 4, or 5, of medium chain fatty acids and monoesters of the respective medium chain fatty acids with a lower polyol.

The useful fatty acid useful as component (A-I) according to the present invention is a medium chain fatty acid, e.g., preferably a monocarboxylic acid having 6 to 20 carbon atoms, preferably 8-16 carbon atoms, more preferably 8-12 carbon atoms. Accordingly, the useful fatty acid can have a formula (I) :

R-C (O) -OH (I)

wherein:

R represents a linear or branched, saturated or unsaturated C ₅-C ₁₉, preferably C ₇-C ₁₅, more preferably C ₇-C ₁₁, hydrocarbyl group, preferably alkyl; and preferably, R is a linear group; and more preferably, R is a linear alkyl.

According to an embodiment of the present invention, R has preferably odd number, e.g., 5, 7, 9, 11, 13, 15, 17 or 19, of carbon atoms. More preferably, R has 7, 9, 11, 13 or 15 carbon atoms; or preferably, R has 7, 9 or 11 carbon atoms.

According to an embodiment of the present invention, the medium chain fatty acid can be used alone or as a combination of two or more fatty acids. Preferably, the medium chain fatty acid is used as a combination of at least 3, 4, or 5 fatty acids.

The useful fatty acid according to the present invention can be preferably at least partially esterified with a polyol.

According to an embodiment of the present invention, the monoester useful as component (A-II) is a monoester of formula (II) :

R-C (O) -OR’ (II)

wherein:

R is as defined in formula (I) .

R’ represents a residue from a polyol. The useful polyol especially contains from 2 to 20 carbon atoms, preferably containing from 2 to 10 carbon atoms and preferably containing from 2 to 6 carbon atoms, such as glycerol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, dipropylene glycol or diethylene glycol.

Preferably, the fatty acid according to formula (I) includes caprylic acid (C8, also called as octoic acid) , capric acid (C10) , lauric acid (C12) , myristic acid (C14) , palmitic acid (C16) , stearic acid (C18) , or arachidic acid (C20) .

More preferably, in the formula (II) , R and R’ are different from one another, wherein R represents a linear C ₇-C ₁₅ alkyl, and R’ represents a residue from a linear polyol containing from 2 to 6 carbon atoms.

According to an embodiment of the present invention, the fatty acid according to formula (I) is preferably used in combination with the monoester according to formula (II) , so as to form the fatty acid-ester mixture (A) . Preferably, the fatty acid and the monoester for the mixture (A) involve the same fatty acid moiety, i.e., the fatty acid of formula (I) and the monoester of formula (II) having the corresponding R group. That is, if a fatty acid of formula (I) having octyl as R, i.e., being a caprylic acid, is used, then, an monoester of formula (II) having octyl as R, i.e., being an monoester of caprylic acid, is used, to form the fatty acid-ester mixture (A) . Also, if two or more fatty acids are concurrently used for the mixture (A) , then the corresponding two or more monoesters respectively having the same fatty acid moieties are used. In other words, according to an embodiment of the present invention, the fatty acid-ester mixture (A) can be deemed as a mixture of two or more fatty acids of formula (I) and the partially esterified monoesters of the each fatty acid.

According to an embodiment of the present invention, the fatty acid-ester mixture (A) comprises a plurality, e.g., at least 3, 4, or 5, of fatty acids of formula (I) and monoesters of formula (II) having the corresponding R groups respectively same as the fatty acids of formula (I) . Corresponding to the fatty acid moieties, it is preferred that a same polyol is used to form the monoesters. That is, for the two more monoesters of formula (II) for the fatty acid-ester mixture (A) , they have the same R’ group. Amongst others, glycerol is particularly used, so as to form glycerides with the variously corresponding fatty acids mentioned above.

According to an embodiment of the present invention, for example, the fatty acid-ester mixture (A) comprises at least 3 fatty acids selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and arachidic acid, to be used as component (A-I) . Meanwhile, the corresponding monoesters of the each fatty acid in component (A-I) are used as component (A-II) . Preferably, the monoesters of component (A-II) is each a glyceride.

Preferably, according to an embodiment of the present invention, the fatty acid component (A-I) comprises caprylic acid, capric acid, and lauric acid. Meanwhile, the corresponding component (A-II) comprises caprylic glyceride (also called as monocaprylin) , capric glyceride (also called as monocaprin) , and lauric glyceride (also called as monolaurin) .

According to an embodiment of the present invention, for example, regarding the fatty acid-ester mixture (A) , the total amount of fatty acids of component (A-I) and the total amount of monoesters of component (A-II) , e.g., glycerides, thereof are present in a ratio ranging from 4: 1 to 1: 1, preferably 3: 1 to 1: 1, more preferably 2.5: 1 to 1.5: 1.

According to an embodiment of the present invention, for example, the fatty acid-ester mixture (A) can be obtained by partially esterifying directly the fatty acid component (A-I) with a polyol to form monoesters, so as to obtain a mixture of fatty acids and the corresponding monoesters as ester component (A-II) . As a polyol is used, it is well understood that a multiester, e.g., diester, triester and the like, may be finally formed. Accordingly, a fatty acid-ester mixture (A) comprising at least 3 fatty acids, monoesters corresponding to the at least 3 fatty acids, and multiesters corresponding to the at least 3 medium chain fatty acids, is still useful for the purpose of the present invention, as long as the main purpose, in particular the anti-itching effect, is not significantly damaged.

For the purpose of the present invention, term “multiester” is provided to mean an ester formed from an esterification of a polyol, wherein more than one hydroxyl group of a polyol molecule is esterified. Accordingly, “diester” and “triester” according to the present invention mean respectively two and three hydroxyl groups of a polyol molecule is esterified.

For example, when glycerol is used to esterify a fatty acid component (A-I) , the useful fatty acid-ester mixture (A) may comprise at least 3 fatty acids, monoesters, diesters and triesters corresponding to the at least 3 fatty acids. For example, the useful fatty acid-ester mixture (A) may comprise caprylic acid, capric acid, and lauric acid, as component (A-I) ; monocaprylin, monocaprin, and monolaurin, as component (A-II) ; and diglyceride and triglyceride of caprylic acid, capric acid, and lauric acid.

When the fatty acid-ester mixture (A) also comprises a multiester, the content of the multiester is not particularly limited, as long as the main purpose, in particular the anti-itching effect, of the mixture (A) is not significantly damaged. For example, the multiester can be used in the mixture (A) in an amount up to 90wt%, preferably 80wt%or less, or preferably 70 wt%or less, or preferably 65 wt%or less.

AVCO

According to an embodiment of the present invention, for example, the fatty acid-ester mixture (A) can be of natural origin. Amongst others, it is quite known that coconut oil comprises a mixture of various C8-C20 fatty acids, especially those having even number of carbon atoms. Thus, it is desirable for the present invention to use a derivative of coconut oil, e.g., an esterified product of coconut oil, as the fatty acid-ester mixture (A) .

Amongst others, a useful derivative of coconut oil is the one called as activated virgin coco oil (AVCO) . Preferably, the coconut oil is esterified with glycerol. An AVCO useful according to the present invention may comprise caprylic acid, capric acid, and lauric acid, as component (A-I) ; monocaprylin, monocaprin, and monolaurin, as component (A-II) .

According to an embodiment of the present invention, for example, as a useful AVCO, the total amount of fatty acids of component (A-I) and the total amount of mono-glycerides of component (A-II) , are present in a ratio ranging from 4: 1 to 1: 1, preferably 3: 1 to 1: 1, more preferably 2.5: 1 to 1.5: 1. More specifically, for example, in exemplary embodiment 1 for AVCO, a useful AVCO may comprise: fatty acid component (A-I) : caprylic acid in an amount of 5-20 wt%, preferably 7-15 wt%, or preferably 8-10 wt%; capric acid in an amount of 1-10 wt%, preferably 2-8 wt%, or preferably 4-7 wt%; and lauric acid in an amount of 20-70 wt%, preferably 30-60 wt%, or preferably 40-55 wt%; and monoester component (A-II) : monocaprylin in an amount of 0.5-15 wt%, preferably 1-10 wt%, or preferably 4-7 wt%; monocaprin in an amount of 0.1-10 wt%, preferably 1-8 wt%, or preferably 3-5 wt%; and monolaurin in an amount of 10-40 wt%, preferably 15-35 wt%, or preferably 20-30 wt%; each relative to the total amount of the fatty acid component (A-I) and the monoester component (A-II) .

An AVCO obtained from the esterification of coconut oil can further comprise diglyceride and triglyceride in addition to the fatty acid component (A-I) and the monoester component (A-II) above. According to an embodiment of the present invention, for example, a useful AVCO may comprise caprylic acid, capric acid, and lauric acid, as component (A-I) ; monocaprylin, monocaprin, and monolaurin, as component (A-II) ; and optionally diglyceride and triglyceride of caprylic acid, capric acid, and lauric acid.

When the AVCO also comprises a multiester selected from diglyceride and triglyceride, the content of the multiester is not particularly limited, e.g., in an amount up to 90wt%, preferably 80wt%or less, or preferably 70 wt%or less, or preferably 65 wt%or less.

According to an embodiment of the present invention, for example, a useful AVCO may comprise: a fatty acid component (A-I) comprising caprylic acid, capric acid, and lauric acid, in an amount of 5-40 wt%, preferably 10-30 wt%, or preferably 20-25 wt%; a monoester component (A-II) comprising monocaprylin, monocaprin, and monolaurin, in an amount of 1-30 wt%, preferably 5-20 wt%, or preferably 10-15 wt%; diglycerides of caprylic acid, capric acid, and lauric acid, in a sum amount of 10-50 wt%, preferably 20-45 wt%, or preferably 30-40 wt%; and triglycerides of caprylic acid, capric acid, and lauric acid, in a sum amount of 10-70 wt%, preferably 15-50 wt%, or preferably 20-30 wt%; each relative to the total amount of the AVCO.

A useful AVCO can be preferably one prepared according to the teaching by EP 1973415, which disclosure is incorporated herein by reference. Accordingly, an exemplary AVCO can comprise: 24.63 mg/g caprylic acid (C8) , 17.81 mg/g capric acid (C10) , 133.70 mg/g lauric acid (C12) and 11.82 mg/g monocaprylin, 8.29 mg/g monocaprin and 57.16 mg/g monolaurin; or 23.10 mg/g caprylic acid (C8) , 16.08 mg/g capric acid (C10) , 116.81 mg/g lauric acid (C12) and 16.04 mg/g monocaprylin, 10.35 mg/g monocaprin and 75.54 mg/g monolaurin; each relative to the total weight of the AVCO; and preferably, the AVCO is derived from catalyzing coconut oil with 1, 3-specific lipase and subjecting it to glycerolysis.

According to an embodiment of the present invention, the composition comprises, as the fatty acid-ester mixture (A) , an amount ranging from 0.1%to 40%by weight, preferably from 0.5%to 35%by weight, more preferably from 1%to 30%by weight, relative to the total weight of the microemulsion.

The fatty acid-ester mixture (A) may be present in the composition according to the present invention in an amount ranging from 0.01%to 10%by weight, preferably ranging from 0.1%to 5%by weight, or preferably ranging from 0.3%to 1.5%by weight, relative to the total weight of the composition.

Additional oils

The oil phase may optionally comprise additional oils conventionally used for cosmetic use and/or to form a microemulsion.

The additional oils may be volatile or non-volatile.

The term "volatile oil" refers to any non-aqueous medium capable of evaporating from the skin or lips, in less than one hour, at room temperature (20-25℃) and atmospheric pressure (760 mmHg) .

More specifically, the volatile oil may be a volatile cosmetic oil, liquid at room temperature. More specifically, a volatile oil has an evaporation rate of between 0.01 and 200mg/cm ²/min, inclusive.

The term "non-volatile oil" is intended to mean an oil remaining on the skin or keratin fiber at ambient temperature and atmospheric pressure.

More specifically, a non-volatile oil has an evaporation rate strictly below 0.01 mg/cm ²/min.

The additional oils that are suitable for the present invention may be hydrocarbon-based, silicone-based or fluorine-based. According to a preferred embodiment of the present invention, the composition is free of silicone-based oil.

According to the present invention, the term "silicone oil" refers to an oil including at least one silicon atom, and in particular at least on Si-O group.

The term "fluorine oil" refers to an oil including at least one fluorine atom.

The term "hydrocarbon-based oil" refers to an oil containing primarily hydrogen and carbon atoms.

The oils may optionally include oxygen, nitrogen, sulfur and/or phosphorus atoms, for example, in the form of hydroxyl or acid radicals.

More preferably, the composition of the present invention comprises hydrocarbon oil (s) .

Specifically, the volatile oils may be chosen from hydrocarbon oils having 8 to 16 carbon atoms, and in particular branched C ₈-C ₁₆ alkanes (also called isoparaffins or isoalkanes) , such as isododecane (also called 2, 2, 4, 4, 6-pentamethylheptane) , isodecane, isohexadecane, and, for example, the oils sold under the trade names

or

It is also possible to cite, as a hydrocarbon volatile oil, linear C ₉-C ₁₇ alkanes, such as dodecane (C ₁₂) and tetradecane (C ₁₄) , sold respectively under the names

12-97 and

14-97 (Sasol) , and, as alkanes obtained according to the method described in the international application WO 2007/068371 A1, such as the undecane (C ₁₁) and tridecane (C ₁₃) mixture sold under the name

UT (Cognis) .

The non-volatile oils may, in particular, be chosen from among the non-volatile hydrocarbon oils.

It is possible to cite, as a non-volatile hydrocarbon oil:

- hydrocarbon oils of animal origin, such as perhydrosqualene,

- hydrocarbon oils of plant origin, such as phytostearyl esters, for instance phytostearyl oleate, phytostearyl isostearate and lauroyl/octyldodecyl/phytostearyl glutamate (AJINOMOTO, ELDEW PS203) , diesters such as diisopropyl sebacate, triglycerides constituted of fatty acid esters of glycerol, in particular in which the fatty acids may have chain lengths ranging from C ₄to C ₃₆, and in particular from C ₁₈ to C ₃₆, it being possible for these oils to be linear or branched, and saturated or unsaturated; these oils may in particular be heptanoic or octanoic triglycerides, shea oil, alfalfa oil, poppy seed oil, pumpkin oil, millet oil, barley oil, quinoa oil, rye oil, candlenut oil, passionflower oil, aloe oil, sweet almond oil, peach kernel oil, groundnut oil, argan oil, avocado oil, baobab oil, barrage oil, broccoli oil, calendula oil, camelina oil, canola oil, carrot oil, safflower oil, hemp oil, rapeseed oil, cotton seed oil, coconut oil, marrow seed oil, wheat germ oil, jojoba oil, lily oil, macadamia oil, corn oil, meadowfoam oil, St. John's Wort oil, monoi oil, hazelnut oil, apricot kernel oil, nut oil, olive oil, evening primrose oil, palm oil, blackcurrant seed oil, kiwi seed oil, grape seed oil, pistachio oil, pumpkin oil, winter squash oil, quinoa oil, musk rose oil, sesame oil, soya oil, sunflower oil, castor oil and watermelon oil, and mixtures thereof, or alternatively caprylic/capric acid triglycerides, for instance those sold by the StEarineries Dubois company or those sold under the names Miglyol

and

by the Dynamit Nobel company,

- linear or branched hydrocarbons of mineral or synthetic origin, such as liquid paraffins and derivatives thereof, petroleum jelly, polydecenes, polybutenes, hydrogenated polyisobutene such as Parleam, squalane;

- ether oils having from 10 to 40 carbon atoms; for instance, ether oils of the formula (III) ,

R ₃-O-R ₄ formula (III)

In the formula (III) :

R ₃ and R ₄, which may be identical or different, denote a linear or branched C ₆-C ₂₅ alkyl or alkenyl radical, R ₃ and R ₄ being chosen such that the ether is liquid at a temperature of less than or equal to 25℃.

According to the present invention, the term “ether oil” means oil that is liquid at room temperature (25℃) comprising at least one ether functional group.

Preferably, the ether of formula (III) is chosen from compounds for which the radicals R ₃ and R ₄, which may be identical or different, denote a linear or branched C ₆-C ₁₂ alkyl or alkenyl radical.

More particularly, according to the present invention, the radicals R ₃ and R ₄may be identical alkyl radical.

Amongst ether of formula (III) , the preferred dialkyl ether is chosen from di-n-hexyl ether, di-n-heptyl ether, di-n-octyl ether, di-n-nonyl ether, di-n-decyl ether, di-isodecyl ether, di-n-dodecyl ether, di-n-eteradecyl ether, di-n-hexadecyl ether, di-n-oxtadecyl ether, or a mixture thereof.

R ₃ and R ₄ preferably denote a C ₈ radical.

The dialkyl ethers that may be used according to the invention may be soluble or insoluble in the compositions, but are preferably insoluble.

These compounds may be prepared according to the process described in patent application DE 41 27 230.

Alternatively, a di-n-octyl ether (INCI name: dicaprylyl ether) that may be used in the context of the present invention. Such product is commercially available, for example those sold under the name

OE by the company Cognis (BASF) , or

OE by the company Ecogreen Oleochemicals;

According to an embodiment of the invention, at least one of the additional oil may be present in an amount ranging from 0.01%to 40%by weight, preferably ranging from 0.1%to 30%by weight, relative to the total weight of the microemulsion composition.

According to an embodiment of the invention, the oil phase is present in an amount ranging from 1%to 50%by weight, preferably ranging from 5%to 30%by weight, relative to the total weight of the microemulsion composition.

Aqueous phase

According to the present invention, the microemulsion composition comprises an aqueous phase, as a continuous phase. Said aqueous phase is preferably present in an amount ranging from 40%to 99%by weight, more preferably from 50%to 85%by weight of the total weight of the composition.

The aqueous phase may comprise solvent, e.g., water and at least one organic solvent miscible with water or mixtures thereof.

Solvent (B)

The composition according to the invention can advantageously comprise one or more solvent (B) e.g., water and/or organic solvent, in the aqueous phase.

Water

The microemulsion composition according to the invention comprises water in a content of 0.5%to 40%by weight relative to the total weight of the composition (I) . The water content in the composition according to the invention preferably ranges from 5%to 40%by weight, more preferably from 10%to 35%by weight, or from 15%to 30%by weight, relative to the total weight of the composition.

Organic solvent

The composition according to the invention may also comprise one or more organic solvents, preferably water-soluble organic solvents (solubility of greater than or equal to 5%in water at 25℃ and at atmospheric pressure) .

Examples of the organic solvents that may be mentioned include linear or branched, and preferably saturated, monoalcohols or diols, comprising 2 to 10 carbon atoms, such as ethyl alcohol, isopropyl alcohol, hexylene glycol (2-methyl-2, 4-pentanediol) , neopentyl glycol and 3-methyl-1, 5-pentanediol, butylene glycol, dipropylene glycol and propylene glycol; aromatic alcohols such as phenylethyl alcohol; polyols containing more than two hydroxyl functions, such as glycerol; polyol ethers, for instance ethylene glycol monomethyl, monoethyl and monobutyl ether, propylene glycol or ethers thereof, for instance propylene glycol monomethyl ether; and also diethylene glycol alkyl ethers, especially C ₁-C ₄ alkyl ethers, for instance diethylene glycol monoethyl ether or monobutyl ether, alone or as a mixture.

The organic solvents, when they are present, generally represent between 1%and 20%by weight relative to the total weight of the composition according to the invention, and preferably between 2%and 15%by weight, or between 8%and 12%by weight.

The total solvent is generally present in the composition in an amount from 10%to 50%, such as from 20%to 40%, relative to the total weight of the composition including all ranges and subranges therebetween.

Solubilizer/Nonionic surfactant (C)

The fatty acid-ester mixture (A) , in particular AVCO, is incorporated in an oil phase of an oil-in-water (O/W) microemulsion according to the present invention. Accordingly, a solubilizer is preferably comprised in the aqueous phase. For the purpose of well suspension of the oil phase, the solubilizer is preferably a nonionic surfactant or a mixture thereof, more preferably a complex of solubilizers. As solubilizer, in particular that for the oil-in-water microemulsion, a water-soluble organic solvent mentioned above, e.g., alcohols, such as ethanol, propanol and the like, may be used as a solubilizer, especially used for the complex.

Among the useful nonionic surfactants according to the invention, mention may be made, alone or as mixtures, of fatty alcohols, α-diols and alkylphenols, these three types of compound being oxyalkylated such as polyethoxylated and/or polypropoxylated and/or polyglycerolated and containing a fatty chain comprising, for example, 6 to 40 carbon atoms, the number of alkylene oxide such as ethylene oxide or propylene oxide groups possibly ranging especially from 2 to 50 and/or the number of glycerol groups possibly ranging especially from 2 to 30. Mention may also be made of copolymers of ethylene oxide and propylene oxide, condensates of ethylene oxide and of propylene oxide with fatty alcohols; polyethoxylated fatty amides preferably having from 2 to 30 mol of ethylene oxide, polyglycerolated fatty amides containing on average 1 to 5, and in particular 1.5 to 4 glycerol groups, ethoxylated fatty acid esters of sorbitan containing from 2 to 30 mol of ethylene oxide, fatty acid esters of sucrose, fatty acid esters of polyethylene glycol, alkylpolyglycosides, N-alkylglucamine derivatives, amine oxides such as (C10-C14) alkylamine oxides or N-acylaminopropylmorpholine oxides.

Preferably the nonionic surfactant is chosen from:

· (poly) ethoxylated fatty alcohols;

· glycerolated fatty alcohols;

· alkylpolyglycosides.

wherein "fatty chain" means a linear or branched, saturated or unsaturated hydrocarbon-based chain comprising from 6 to 30 carbon atoms and preferably from 8 to 30 carbon atoms.

As regards the alkyl polyglycosides or APGs, these compounds are well known to a person skilled in the art.

These compounds are represented more particularly by the following general formula:

in which formula (XI) :

R ₁ represents a saturated or unsaturated, and linear or branched alkyl and/or alkenyl radical comprising from 8 to 24 carbon atoms or an alkylphenyl radical, wherein the linear or branched alkyl radical of which comprises from 8 to 24 carbon atoms;

R ₂ represents an alkylene radical comprising approximately from 2 to 4 carbon atoms;

G represents a sugar unit comprising from 5 to 6 carbon atoms;

a denotes a value ranging from 0 to 10 and preferably from 0 to 4, and

b denotes a value ranging from 1 to 15.

Preferred alkyl polyglycosides useful in the composition of the present invention are compounds of formula (XI) in which R ₁ more particularly denotes a saturated or unsaturated and linear or branched alkyl radical comprising from 8 to 18 carbon atoms, adenotes a value ranging from 0 to 3 and more particularly still equal to 0, and G can denote glucose, fructose or galactose, preferably glucose.

The degree of polymerization, i.e. the value of b in the formula (I) , can range from 1 to 15 and preferably from 1 to 4. The average degree of polymerization is more particularly between 1 and 2 and even more preferably from 1.1 to 1.5.

The glycoside bonds between the sugar units are of 1-6 or 1-4 type and preferably of 1-4 type.

Compounds of formula (I) are represented in particular by the products sold by Cognis under the names

(600 CS/U, 1200 and 2000) or

(818, 1200 and 2000) . Use may also be made of the caprylyl/capryl glucoside products sold by Seppic under the names Triton CG 110 (or Oramix CG 110) and Triton CG 312 (or

NS 10) , the products sold by BASF under the name Lutensol GD 70 or the products sold by Chem Y under the name AG10 LK.

Use may also be made, for example, of C ₈-C ₁₆ alkyl 1, 4-polyglucoside as a 53%aqueous solution, sold by Cognis under the reference

818 UP.

As regards the mono- or polyglycerolated surfactants, they preferably comprise on average from 1 to 30 glycerol groups, more particularly from 1 to 10 glycerol groups and in particular from 1.5 to 5.

The monoglycerolated or polyglycerolated surfactants are preferably chosen from the compounds of the following formulae:

R”O [CH ₂CH (CH ₂OH) O] _mH,

R”O [CH ₂CH (OH) CH ₂O] _mH or

R”O [CH (CH ₂OH) CH ₂O] _mH;

in which formulae:

· R” represents a saturated or unsaturated, linear or branched hydrocarbon-based radical comprising from 8 to 40 carbon atoms and preferably from 10 to 30 carbon atoms; m is an integer between 1 and 30, preferably between 1 and 10 and more particularly from 1.5 to 6; R” may optionally comprise heteroatoms, for instance oxygen and nitrogen. In particular, R” may optionally comprise one or more hydroxyl and/or ether and/or amide groups. R” preferably denotes mono-or polyhydroxylated C ₁₀-C ₂₀ alkyl, and/or alkenyl radicals.

Use may be made, for example, of the polyglycerolated (3.5 mol) hydroxylauryl ether sold under the name

NF from Chimex.

The (poly) ethoxylated fatty alcohols that are suitable for performing the invention are chosen more particularly from alcohols containing from 8 to 30 carbon atoms, and preferably from 12 to 22 carbon atoms.

The (poly) ethoxylated fatty alcohols more particularly contain one or more linear or branched, saturated or unsaturated hydrocarbon-based groups, comprising 8 to 30 carbon atoms, which are optionally substituted, in particular with one or more (in particular 1 to 4) hydroxyl groups. If they are unsaturated, these compounds may comprise one to three conjugated or non-conjugated carbon-carbon double bonds.

The (poly) ethoxylated fatty alcohol (s) preferably have the following formula (XII) :

with

- R ₃ representing a linear or branched C ₈-C ₄₀ alkyl or alkenyl group and preferably C ₈-C ₃₀ alkyl or alkenyl group, optionally substituted with one or more hydroxyl groups, and

- c is an integer between 1 and 200 inclusive, preferably between 2 and 50 and more particularly between 8 and 30, such as 20.

The (poly) ethoxylated fatty alcohols are more particularly fatty alcohols comprising from 8 to 22 carbon atoms, oxyethylenated with 1 to 30 mol of ethylene oxide (1 to 30 OE) . Among these, mention may be made more particularly of lauryl alcohol 2 OE, lauryl alcohol 3 OE, decyl alcohol 3 OE, decyl alcohol 5 OE and oleyl alcohol 20 OE.

Mixtures of these (poly) oxyethylenated fatty alcohols may also be used.

Among the nonionic surfactants, use is preferably made of C ₆-C ₂₄ alkyl polyglucosides and (poly) ethoxylated fatty alcohols, C ₆-C ₁₆ alkyl polyglucosides are more particularly used.

According to the invention, the composition may comprise at least one fatty acid ester of glycerol and/or of polyglycerol for use as a nonionic surfactant, which is different from the ester useful for the fatty acid-ester mixture (A) according to the present invention, e.g., glyceryl esters of C ₁₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof.

According to a preferred embodiment, the fatty acid ester (s) of polyglycerol is (are) chosen from esters resulting from the reaction of polyglycerol comprising from 2 to 12 glycerol units, preferably from 3 to 10 glycerol units, and of at least one fatty acid containing from 8 to 24 carbon atoms, preferably from 8 to 22 carbon atoms, better still from 10 to 20 carbon atoms and even better still from 10 to 18 carbon atoms. The fatty acids containing from 8 to 24 carbon atoms may be linear or branched, and saturated or unsaturated.

The fatty acids may be chosen from oleic acid, stearic acid, isostearic acid, lauric acid, palmitic acid, myristic acid, linoleic acid, capric acid and caprylic acid, or mixtures thereof.

The fatty acid esters of polyglycerol can be chosen from monoesters, diesters, triesters and tetraesters, polyesters and mixtures thereof. Use is preferably made of esters with a low degree of esterification, for instance fatty acid monoesters, diesters or triesters of polyglycerol, or a mixture. The fatty acid ester of polyglycerol can be in the form of a mixture of esters with a low degree of esterification, for instance a mixture of monoester and diester or a mixture of monoester, diester and triester.

According to one embodiment, the fatty acid ester of polyglycerol is chosen from esters resulting from the reaction of polyglycerol comprising from 3 to 10 glycerol units and of at least one fatty acid containing from 8 to 20 carbon atoms, preferably from 10 to 18 carbon atoms, such as oleic acid or linoleic acid.

Mention may in particular be made of polyglyceryl-2 distearate, in particular as sold by NIHON EMULSION under the name Emalex PGSA; polyglyceryl-10 decastearate, in particular as sold by TAIYO KAGAKU under the name Sunsoft Q-1810S; glyceryl oleate, in particular as sold by COGNIS under the name Monomuls 90-O 18; glyceryl stearate, in particular as sold by COGNIS under the name Cutina GMS V; polyglyceryl-5 hexastearate, in particular as sold by TAIYO KAGAKU under the name Sunsoft A-186E; polyglyceryl-10 pentaoleate, in particular as sold by TAIYO KAGAKU under the name Sunsoft Q-175S; polyglyceryl-10 pentastearate, in particular as sold by TAIYO KAGAKU under the name Sunsoft Q-185S; polyglyceryl-4 isostearate, in particular as sold by EVONIK GOLDSCHMIDT under the name Isolan GI 34; diisostearoyl polyglyceryl-3 dimer dilinoleate, in particular as sold by EVONIK GOLDSCHMIDT under the name Isolan PDI; polyglyceryl-2 oleate, in particular as sold by TAIYO KAGAKU under the name Sunsoft Q-17B; polyglyceryl-5 trimyristate, in particular as sold by TAIYO KAGAKU under the name Sunsoft A-143E; polyglyceryl-2 caprylate, in particular as sold by TAIYO KAGAKU under the name Sunsoft Q-81B; polyglyceryl-2 laurate, in particular as sold by TAIYO KAGAKU under the name Sunsoft Q-12D.

According to one particular embodiment, the fatty acid which is suitable for the reaction with the ester (s) of polyglycerol comprises at least one hydroxyl group. This is the case for ricinoleic acid. Mention may in particular be made of polyglyceryl-3 ricinoleate (and) sorbitan isostearate, in particular as sold by CRODA under the name Arlacel 1690, polyglyceryl-3 ricinoleate, in particular as sold by AARHUSKARLSHAMN under the name Akoline PGPR.

According to another embodiment, the fatty acid which is suitable for the reaction with the ester (s) of polyglycerol is a polyacid comprising at least one hydroxyl group.

According to one embodiment, the sorbitan esters of fatty acids (C ₈-C ₂₄ fatty acid esters) , and the oxyalkylenated derivatives thereof may be used as the nonionic surfactant. Oxyalkylenated fatty acid esters of sorbitan comprise, for example, from 20 to 100 EO, for example those sold under the trade names Tween 20, Tween 60 or Tween 80.

Examples of the useful nonionic surfactants may thus comprise esters of polyols and of fatty acids with a saturated or unsaturated chain containing, for example, from 18 to 24 carbon atoms and the oxyalkylenated derivatives thereof, i.e. derivatives containing oxyethylenated and/or oxypropylenated units, such as the glyceryl esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the polyethylene glycol esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the sorbitol esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the sorbitan esters of fatty acids (C ₈-C ₂₄ fatty acid esters) , and the oxyalkylenated derivatives thereof; the sugar (sucrose, glucose or alkylglucose) esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; fatty alcohol ethers; the sugar ethers of C ₈-C ₂₄ fatty alcohols, and mixtures thereof.

The at least one nonionic surfactant may be present in the composition according to the present invention in an amount from 15%to 80%, such as from 20%to 70%, or from 25%to 50%, relative to the total weight of the composition including all ranges and subranges therebetween.

According to an embodiment of the invention, a complex of solubilizers is used to improve oil suspension in micelle and enhance transparency of a shampoo product. A complex of at least one the nonionic surfactant above with an alcohol useful as the organic solvent above is preferable. For example, in a transparent shampoo with sulfate surfactant, an effective complex of solubilizers may comprise 0.1-8%caprylyl/capryl glucoside and 0.1-3.5%alcohol, while in a transparent shampoo without sulfate surfactant, an effective complex of solubilizers may comprise 3-6%POLYSORBATE 20 and 2-4.5%alcohol, relative to the total weight of the composition.

Additional Additives

According to various embodiments, the compositions of the present invention are provided for application to keratin materials, such as skin, scalp or hair. In accordance with these embodiments, the compositions of the present invention can comprise various ingredients conventionally useful in compositions for caring for and/or cleansing keratin materials, such as, additional surfactant including anionic surfactant and amphoteric surfactant, active ingredients, humectants, additional fatty substances, antidandruff agents, anti-seborrhoea agents, agents for preventing hair loss and/or for promoting hair regrowth, vitamins and provitamins including panthenol, sunscreens, sequestrants, plasticizers, acidifying agents, opacifiers, pearlescent or nacreous agents, antioxidants, hydroxyacids, fragrances and preserving agents.

A non-exhaustive listing of such ingredients can be found in U.S. patent application publication no. 2004/0170586, the entire contents of which is hereby incorporated by reference. Still further examples of such additional ingredients may be found in the International Cosmetic Ingredient Dictionary and Handbook (9 ^th ed. 2002) .

A person skilled in the art will take care to select the optional additional additives and/or the amount thereof such that the advantageous properties of the composition according to the invention are not, or are not substantially, adversely affected by the envisaged addition.

These additives may be selected variously by the person skilled in the art in order to prepare a composition which has the desired properties, for example, consistency or texture. In particular, the additives, if used, and the amounts thereof are particularly determined according to the specific products/applications thereof, e.g., lotion, leave-on conditioner, shampoo, cream, rinse-off conditioner and the like.

These additives may be present in the composition in an amount from 0.01%to 50%relative to the total weight of the composition, including all ranges and subranges therebetween.

Method and use

The composition according to the present invention can be generally prepared according to the general knowledge of a person skilled in the art. Nevertheless, it is to be understood that a person skilled in the art can choose the method of preparation, on the basis of his/her general knowledge, taking into account the nature of the constituents used, for example, their solubility in the vehicle, and the application envisaged for the compositions or the kit.

According to an embodiment, the composition according to the present invention can be used to prepare products for caring for and/or cleansing keratin materials, especially the hair, skin and scalp.

The composition according to the present invention is preferably useful to produce a shampoo product, scalp care products, or even skincare products. According to the detailed discussions above, it is to be understood that the shampoo product, scalp care products, or even skincare products according to the present invention may advantageously have a transparent appearance. Also, according to the detailed discussions above, it is to be understood that composition, and in turn the shampoo product according to the present invention may be free of silicone oil.

The invention will be further illustrated by the following examples, which set forth particularly advantageous embodiments.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the present invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contain certain errors necessarily resulting from the standard deviation found in their respective measurements. The following examples are intended to illustrate the present invention without limiting the scope as a result.

Examples

The ingredient amounts/concentrations in the compositions/formulas described below were expressed in %by weight, relative to the total weight of each composition/formula.

Material:

COCOS NUCIFERA (COCONUT) OIL: activated virgin coconut oil (AVCO) , available from BIOTROPICS

Other materials without specification here were each commercially available.

Example 1

Microemulsions I, II, and comparative microemulsion I’ were respectively formulated:

Table 1:

Table 2:

INCI	Microemulsion II
Tween 80	39.2
Dipropylene glycol	9.8
AVCO	27.5
WATER/AQUA	QS to 100

Microemulsion III was formulated:

Table 3:

INCI	Microemulsion III
POLYSORBATE 20	57.7
Ethanol	3
GLYCERYL OLEATE	5.3
TOCOPHERYL ACETATE	0.02
AVCO	20.7
MENTHOL	4.6
WATER/AQUA	QS to 100

The microemulsions I to III were transparent, whereas the comparative microemulsion I’ was not transparent, i.e., no microemulsion was formed.

Table 4:

Microemulsion	Turbidity (NTU)
I	1.07
II	2.32
I’	Not transparent

Example 2

The above mentioned microemulsions were used to formulate shampoo compositions A, B and D, and comparative composition C, as Tables 4 and 5:

Table 5

Table 6

Table 7

The above listed compositions A-D were prepared according to known manufacturing method of field.

Compositions A-D were obtained in shampoo product according to the present invention. Particularly, compositions A, B and D were transparent, composition C was not transparent.

Example 3

The soothing feeling of the composition A was evaluated. 5 volunteers between age of 25 and 45 applied the composition A on the hair and scalp every day for 3 weeks, followed by 2 weeks without using the composition A. The anti-itchy feeling (soothing feeling) was assessed in the total 5 weeks. Scores of itchy feeling before the application of the composition A was given as a baseline, the scores of itchy feeling after application of the composition A was given every day, the mean difference was shown in Table 8.

Scores were given and calculated as follows:

In the first 3 weeks, each volunteer washed hair with the composition A at every evening, in which the conventional usage of each volunteer was used. In the next 2 weeks, each volunteer washed hair with a standard shampoo without AVCO also at every evening, in which the conventional usage of each volunteer was still used.

Volunteers gave scores to the itching feeling, where:

0 meant unchanged;

-1 meant fairly improved;

-2 meant significantly improved; and

-3 meant substantially free of itching feeling.

The average scores of the 5 volunteers were counted every day, and were calculated for the averages for every week. The average scores for the total 5 weeks were provided in Table 8 below.

Table 8

	Week 1	Week 2	Week 3	Week 4	Week 5
Composition A	-0.5	-1.0	-1.7	-1.3	-1.1
Composition D	-0.7	-0.9	-1.5	-1.3	-1.1

Referring to Table 8, less the score, less the itchy feeling was. It was observed that the compositions A and D each showed a very good and long term anti-itchy feeling, even 2 weeks after the last application of the compositions.

Claims

An oil-in-water microemulsion composition useful in a product for caring for and/or cleansing keratin materials, comprising:

an oil phase comprising

(A) a fatty acid-ester mixture comprising:

(A-I) . a fatty acid component comprising a plurality, e.g., at least 3, 4, or 5, of medium chain fatty acids, and

(A-II) . an ester component comprising a plurality, e.g., at least 3, 4, or 5, of monoesters of medium chain fatty acids;

wherein the medium chain fatty acid denotes a monocarboxylic acid having 6 to 20 carbon atoms; and

an aqueous phase comprising

(B) a solvent, e.g., water and/or at least one alcohol, and

(C) at least one non-ionic surfactant.
The microemulsion composition according to claim 1, wherein the fatty acid-ester mixture (A) comprises at least 3 fatty acids selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and arachidic acid, to be used as component (A-I) ; and the corresponding glycerides of the each fatty acid in component (A-I) are used as component (A-II) ;

and preferably, the fatty acid component (A-I) comprises caprylic acid, capric acid, and lauric acid; while the corresponding component (A-II) comprises monocaprylin, monocaprin, and monolaurin; and

wherein the total amount of fatty acids of component (A-I) and the total amount of monoesters of component (A-II) are present in a ratio ranging from 4: 1 to 1: 1, preferably 3: 1 to 1: 1, more preferably 2.5: 1 to 1.5: 1.
The microemulsion composition according to claim 1 or 2, wherein the fatty acid-ester mixture (A) is activated virgin coco oil comprising:

- fatty acid component (A-I) :

caprylic acid in an amount of 5-20 wt%, preferably 7-15 wt%, or preferably 8-10 wt%;

capric acid in an amount of 1-10 wt%, preferably 2-8 wt%, or preferably 4-7 wt%; and

lauric acid in an amount of 20-70 wt%, preferably 30-60 wt%, or preferably 40-55 wt%;

and

- monoester component (A-II) :

monocaprylin in an amount of 0.5-15 wt%, preferably 1-10 wt%, or preferably 4-7 wt%;

monocaprin in an amount of 0.1-10 wt%, preferably 1-8 wt%, or preferably 3-5 wt%; and

monolaurin in an amount of 10-40 wt%, preferably 15-35 wt%, or preferably 20-30 wt%;

each relative to the total amount of the fatty acid component (A-I) and the monoester component (A-II) .
The microemulsion composition according to claim 3, wherein the activated virgin coco oil comprises:

- a fatty acid component (A-I) comprising caprylic acid, capric acid, and lauric acid, in an amount of 5-40 wt%, preferably 10-30 wt%, or preferably 20-25 wt%;

- a monoester component (A-II) comprising monocaprylin, monocaprin, and monolaurin, in an amount of 1-30 wt%, preferably 5-20 wt%, or preferably 10-15 wt%;

- diglycerides of caprylic acid, capric acid, and lauric acid, in a sum amount of 10-50 wt%, preferably 20-45 wt%, or preferably 30-40 wt%; and

- triglycerides of caprylic acid, capric acid, and lauric acid, in a sum amount of 10-70 wt%, preferably 15-50 wt%, or preferably 20-30 wt%;

each relative to the total amount of the activated virgin coco oil.
The microemulsion composition according to any one of the preceding claims, wherein the oil phase is present in an amount ranging from 1%to 50%by weight, preferably ranging from 5%to 30%by weight, relative to the total weight of the composition.
The microemulsion composition according to any one of the preceding claims, wherein the at least one nonionic surfactant (C) is selected from the group consisting of glyceryl esters of C ₁₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the polyethylene glycol esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the sorbitol esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the sorbitan esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; the sugar esters of C ₈-C ₂₄ fatty acids, and the oxyalkylenated derivatives thereof; fatty alcohol ethers; the sugar ethers of C ₈-C ₂₄ fatty alcohols, and mixtures thereof.
The microemulsion composition according to any one of the preceding claims, wherein the nonionic surfactant (C) is present in the composition in an amount from 30%to 80%, such as from 40%to 70%, relative to the total weight of the composition including all ranges and subranges therebetween.
The microemulsion composition according to any one of the preceding claims, wherein the solvent (B) is selected from the group consisting of water and at least one organic solvent miscible with water.
The microemulsion composition according to any one of the preceding claims, wherein the solvent (B) is present in the composition in an amount from 10%to 50%, such as from 20%to 40%, relative to the total weight of the composition including all ranges and subranges therebetween.
The microemulsion composition according to any one of the preceding claims, comprising a complex of components (B) and (C) comprising 0.1-8%caprylyl/capryl glucoside and 0.1-3.5%alcohol, or a complex of solubilizers comprising 3-6%POLYSORBATE 20 and 2-4.5%alcohol, relative to the total weight of the composition.
The microemulsion composition according to any one of the preceding claims, in the form of a transparent microemulsion.
A shampoo product comprising the microemulsion composition according to any one of the preceding claims 1-11.
A scalp care product comprising the microemulsion composition according to any one of the preceding claims 1-11.
A skincare product comprising the microemulsion composition according to any one of the preceding claims 1-11.